Commutator



O. KERSTEN.

coMMuTAToR. APPLICATION FILED NOV.25, I9I8.

` Patented May 18, 1920.

OTTO RER-STEIN, 0F DETROIT, MOHIGN.

ociantr'rnfron.

Specification of Letters Eatent.

' Pateatea'nay 1s, 192e.

Application filed November 25, 1918. rSerial No. 264,092.

T 0 all whom t may concern Be it known that l, OTTO Knnsrnn, a citizen of the United States of America, residing at Detroit, in the 'county of lWayne and State of Michigan, have invented certain new and useful improvements in Commutators, of which the following is a' specification, reference being had therein to the accompanying drawings.

My'invention aims to provide a commutator or timer for fthe ignition system of an internal combustion engine, particularly an engine having four spark plugs and coil units and a magneto or batteries associated therewith, so that the commutator may determine the instant at which the spark plugs must tire the explosive mixture in the cylinders ot' the engine. To this end have devised a coinmutator or timer wherein the primary circuit of an ignition system is interrupted or the make and break of the circuit accomplished through the medium of novel contacts movable to and from the stationary contacts, in contradistinction to those contacts which ordinarily have a rolling or wip- 'm0' action relative to each other.

ly invention further aims to provide a commutator which will insurea smooth running engine and facilitate the starting of the' same, and the mechanical construction contributing to these results will be hereinafter described and then claimed.

Reference will now be had to the drawing wherein- Figure l is adiagiiammatic view of the ignition system of an; internal combustion engine; showing the cltmmutato'r in end elevation or at a right angle to the natural position on the engin't; v

Fig. 2 is a rear elevation of the commutator, and I Fig. 3 is a longitudinal sectional view ot' the same.

In the drawing, the reference numeral 1 denotes a conventional :tormof internal combustion engine having spark plugs 2 serving the cylinders of the engine. said spark plugs being electrically connected,y as

at 3, to coil units or a box Il which has the terminals thereof electrically connected, as at 5, to the binding post G ot a commutator casing 7.y The coil units or box t is also electrically connected as at 8. to a magneto or battery (not shown). 'lhi's is the ordinary and well known ignition system wherein a primary circuit 1s adapted to be mamtained by utilizing metallic parts and interruptingthe circuit at the commutator, which is suitably secured .to the engine and is operated through the medium of a cain shaft 9 extending into the commutator casing'7.

The binding posts 6 are suitably insulated from the casing 7 and the inner ends of said binding posts have tungsten points 10. Adjacent the inner ends of the binding posts G are studs or posts 11 suitably connected to the casing 7 and provided with pivoted clevises or. yoles 12. The clevises 'l2 have small apertured ears 13 at one end thereof and large apertured ears let at the opposite end,- thereof, the small apertured ears 13 being pivotally mounted on these studs 11 with a coiled spring 15 encircling each stud between the small ears 13 pivoted thereon. The springs 15 have end convolutions thereof engaging the inner wall 'of the commutator casing 7, and other end fconvolutions engaging in the clevises 12, said springs being constantly under tension so as to shift the clevises when the free ends thereof are released.

Journaled in the free ends of the clevises between the large ears 14 are rollers 16, preferably made of ber or any material. These rollers are adapted to normally engage a roll or head 17 lixed on the end of the shaft 9 within the commutator casing 7 said roll or head having a fiat or inset surface 18 which permits the clevises 12*to fully shift without Contact with the roll 17 due to the tension of the spring 15. The clevises 12, intermediate the ends thereolZ have arms 19 provided with tung-r sten -points 20, and these tungsten points are constantly opposite the tungsten points 10 of the binding posts 6 so as to contact therewith when permitted to do so by the roll' or head 17 presenting iat or inset surface or facet to' one of the rollers 14. `With one ot the rollers out ot contactwith the roll, the full tension ol" the spring associated with the roller causes a positive engagement of the tung. 'en points and there is no danger of the circuit being through the wall.

s will be understood, the structure disclosed embodies a rotating control element, and means for supporting the movable contact of a pair of opposing contacts,"wth the means formed of an elementthe clevis-pivoted at one 'end and having its opposite end formed with a face which is the en arnn erin icing no arranged ko normally www". e plane epproxnnnl 1* i" 'it :ingle with tile axis tbe terininal l cc" act, tlins causing tlie arm end to combinedly produce e structure lniyinc' e general configuration approaching e islizipe in elevation. As result it 1s possible to locate 'the pivot joint of the element e maximum distance from the control element` and yet place it in proximity to structure and yet a Sin'licient dis- Lce from tlie Stationary Contact ne to greycnt liability oli electrical clii'iienlties. zn'riingement sulllcient space is grol led, between adjacent terminal contacts, Mtliin which the if'ollower-tlie roller in the embodiment enorm-man lieve it ment i bout tending to provide int ence in oneretion. rind While these lief are Qreeent, the entir structure can. be produced with :i casing of coingjxiretively small size eren where tlie number ot stittienary contacts euch es to locate tliem in epaeed relation with an angular spacing distance et 9Go, withoutcrowding the interior of tlie casing' or bringing the Zone of operation of one of such lever units into tiret of another unit or witliin the quadyrant delined by adjacent stationary eentects and the Shaft axis, excepting such as might be provided by carrying the element member beyond Such quadrant in supportite contact in opposition to its cooperatingl stationary contact; at the time it permits ay symmetrical' arrangement, in that eecli unit has tlie seme relation with the tern minal with which it cooperates :is every other unit. ln other Words, the structure is Snell is to permit t'ne formation of il compact Whole in which electrical interference is avoided, tbe movement et each unit is nneleeted by that of any other7 and yet provide for a maximnm number of terminals, and the use of a control element of minimum diameter. In addition. tbe erreng'ement is such as to permit the use of a. comparatively large roller as the member in contact with the control element, a. positive advantage under the conditions ot sneed requirements in devices ot' thin kind, tlie diameter of roller permitted causing' the ll.. M. ratio dillerence between the roller and the control element to be small as; com- ;ed prior structures, Wliere n roller irme tlie Yfollower of tbe control element, time narticnler terni of unit permitting free movement ot :i roller olf Such size Awithin tlic :smell splice.

,-.iy :tc-rence to Fig. 2

l 1e conti( i 1 e Y "lo tbe lointli contact in mede or cioe o .in consequence of tliie' conntructive lirrno'enient, rotation olf tile roll or head cai lic contacte to a relative to tno connect caeing the possilnlity ot Short circuit., in connection with the coinnnitutor le reduced to a minimum, l attacli considerable izngoir- 'tance 'to the rtact that 'elle contacte do not 'wipe encli other but nre o'l" positive nizike i i breek electrical conncctiinis7 the inail;- the connections being; automatic and ali' ig mechanically performed. It tlizit tlie number of contitcts del nds upon tlie number ot cylinders in connection with tbc engine7 and while there is illustrated a prelerrcil embodiment ci, my invention., it is to be understood tirait the striu/nral elements nro eneeinptilile to snel; 'variations and n'iodicationrs :is 'tell within tlie scene ot tlie appended claims.

"-,lllizi'lj claim l. lin :i distri plurality of terminal mintziclo spaced substantially in a circular i wien lenlm'tantially concentric with the axis; ot rotation oli a slint't, and wherein the opposing cooperating contacts are mow-dile toward and from such e/ationary contacts, a control structure carried by and movable with the sliai't, and. means `for supporting' said movable contacts individually, Said means including a conA tactcarrying member, a pivoted element having a tac at ite` free end adapted to contact with the control Structure, said inembei' being permanently positioned relative to the element. :ind projecting from eucli clement on :i plane intersecting: :i` plone connecting); tbc pivot point and said taco with the point ot' intersection ot tbe planes lo* cated between and spaced 'from both axis and -face olf tlie clement, said clement and Said member colnbiiiedly producing; nn npproxinuitely Y-sliape configuration in elevang coninnil'ntor boring a tion7 seid control structure having; a face j able contacts individually, said means including a unit having a configuration in elevation approaching` that of Y-shape and havingjr a pivotal axis and a face normally maintained in contact with the control element` the unit contact support being` positioned approximately on a plane intersecting a plane connecting the unit axis and said face at right angles with the point ot' intersection between and spaced from both axis and face. each unit havingv the same positional relation with its terminal contact and the shaft as an adjacent unit, whereby a symmetrical arrangement ot units is provided within the connnntator casing.

A. commutator as in claim i2 characterized in that the pivot axis ol cach unit is positioned outside ot' a line corresi)ondingto a circle the radins of which corresponds to the distance between a terminal contact and the shaft axis,

el. ln a distributing` commutator having' a pluralityv of terminal contacts substantially uniformly spaced in a circular series substantially concentric with the axis oi rotation of a shaft, and wherein the opposini` cooperating contacts are movable toward and from such terminal contacts, a control element carried by and movable with the shaft, and means for supporting said movable contacts individually, said means including contactarrying pivoted units, corresponding in number to the number of terminal units, each unit including a sheetmetal clevis having` opposed apertured ears at one end to receive the unit pivot and having its opposite end formed to normally bear on the control element, an arm projecting' from the clevis in a manner to produce therewith a general configuration in elevation approachingv Y-shape, said arm carrying' the movable contact, a 'pin `.forming the unit pivot, and a spring,` on said pin and cooperative with the unit and casing` to normally maintain contact of unit and the control element.

5. commntator as in claim el characterized in that the clevis free end is in the form of apertured ears between which is located a roller normally bearing on the control element.

ln testimony whereoiI I aflix my signature in the presence ot' two witnesses.

GTT() KERSTEN.

lllitnesses E Kann lil. BUTLER, ANXA M. Dona. 

